The invention relates to a method and an apparatus for processing sheets of different sizes to a mail item. Here, the sheets may also comprise, for instance, address carriers, brochures, reply cards, prepaid envelopes, carriers with a plastic card, etc.
For assembling mail items containing sheets of different sizes, different solutions are known. From American patent publications U.S. Pat. Nos. 4,077,181 and 4,972,655, it is known to fold sheets which have a size in a conveying direction which is larger than the size of the envelope in conveying direction, and then to add a sheet which has a size in conveying direction which is smaller than the size of the envelope in the conveying direction and to insert the set of sheets thus formed into the envelope. However, this imposes limitations on the possible sizes of the small sheet.
From European patent publication 0 556 922, it is known to gather sheets of different sizes in conveying direction prior to the folding, the sheets being fed to the folding station for folding with trailing edges being in alignment. Although this opens up the possibility for sheets of a smaller size in conveying direction which are not folded to be processed together with larger sheets to be folded to form mail items, this processing method also entails limitations with regard to the possible sizes of the small sheet, because reliable and careful folding requires that, for each sheet, a minimum distance of the leading edge to the nearest folding line is observed.
Known from practice is an apparatus marketed by Printed Forms Equipment under the name of “Minimailer” for assembling mail items, with which a small sheet can be placed on a larger sheet such that, after folding, the small sheet is located between the two folds, seen in a direction perpendicular to the folds. However, this also imposes limitations on the possible sizes of the sheet, in that these are limited to the folding length of the panel between the two folds.